Gmail users are the newest targets of a phishing scam that allows hackers to infiltrate their accounts. In the latest attack, a fake browser window that resembles Google's sign-in page tricks people into entering their log-in info. That data then goes straight to a third party.

How does the scam work? Cyber criminals send emails that appear to be from friends or about an interesting subject. The messages contain innocent-looking attachments. When the receiver clicks on the file, a new tab that looks just like Google's sign-in page opens.

"Hackers send out info that makes you interested by faking an acquaintance or related-subject matter," cyber security expert Dale Cooper told us Wednesday. "Once you click on it, they know they have a 'good email' and they work to reel you in. Then, they use different techniques to gather information needed to go deeper."

Cooper is the founder of Lexington-based cyber safety and online monitoring company Xact Communications. He has more than 20 years of experience in the communication and security industries.

Unfortunately, campaigns like this are happening more frequently - and they're getting more sophisticated, according to the cybersecurity veteran. Hackers frequently trick people by sending emails from false addresses or using Photoshopped images that look like real browsers. Even the locations of these virtual assaults are becoming increasingly difficult to track. Many breaches appear to be from servers in US data centers, but hackers are actually located overseas and are able to scramble their locations.

How can people protect themselves from attacks?

"Always look and be aware before you click, especially on phones, where we tend to just go 100 miles per hour on replies," Cooper advised. He also recommends double-checking URLs and host names.

"Question any email that you are not familiar with, especially emails from senders that are financial institutions asking for login info or personal updates," he added. Most banks have precautions for avoiding fraudulent emails.